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History of Changes for Study: NCT02507180
Safely Ruling Out Deep Vein Thrombosis in Pregnancy With the LEFt Clinical Decision Rule and D-Dimer (LEaD)
Latest version (submitted February 25, 2020) on ClinicalTrials.gov
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Study Record Versions
Version A B Submitted Date Changes
1 July 22, 2015 None (earliest Version on record)
2 September 13, 2016 Recruitment Status, Study Status, Conditions, IPDSharing, Contacts/Locations and Oversight
3 November 17, 2017 Contacts/Locations, Study Status, Eligibility, Conditions, Study Description and Sponsor/Collaborators
4 January 7, 2019 Contacts/Locations, Outcome Measures, Study Status, Study Description, Oversight, Eligibility and Conditions
5 February 25, 2020 Recruitment Status, Contacts/Locations, Study Status and Sponsor/Collaborators
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Study NCT02507180
Submitted Date:  July 22, 2015 (v1)

Open or close this module Study Identification
Unique Protocol ID: 20150546-01H
Brief Title: Safely Ruling Out Deep Vein Thrombosis in Pregnancy With the LEFt Clinical Decision Rule and D-Dimer (LEaD)
Official Title: Safely Ruling Out Deep Vein Thrombosis in Pregnancy With the LEFt Clinical Decision Rule and D-Dimer: the LEaD Study. A Prospective Cohort Study.
Secondary IDs:
Open or close this module Study Status
Record Verification: July 2015
Overall Status: Not yet recruiting
Study Start: September 2015
Primary Completion: September 2018 [Anticipated]
Study Completion: December 2018 [Anticipated]
First Submitted: July 22, 2015
First Submitted that
Met QC Criteria:
July 22, 2015
First Posted: July 23, 2015 [Estimate]
Last Update Submitted that
Met QC Criteria:
July 22, 2015
Last Update Posted: July 23, 2015 [Estimate]
Open or close this module Sponsor/Collaborators
Sponsor: Ottawa Hospital Research Institute
Responsible Party: Sponsor
Collaborators:
Open or close this module Oversight
U.S. FDA-regulated Drug:
U.S. FDA-regulated Device:
Data Monitoring: Yes
Open or close this module Study Description
Brief Summary: This is prospective cohort study, in pregnant women who present with signs and symptoms of possible deep vein thrombosis. All patients will have the same method of assessment of their DVT symptoms (the LEFt clinical decision rule will be applied and D-dimer test will be done) to determine if a compression ultrasound is required. All patients will be followed for a period of 3 months.
Detailed Description:

VTE is a leading cause of maternal death in the developed world. Suspected DVT in pregnancy is a common clinical problem faced by clinicians daily. The only validated method to exclude DVT in pregnancy requires leg vein CUS imaging. This imaging modality is costly and has limited availability (only available in radiology departments and, usually, only during weekday daytime hours) often necessitating referral to the emergency room for initiation of heparin injections until leg vein CUS can be obtained. A simple and seemingly powerful clinical decision rule (LEFt) and a simple blood test (D-dimer) may be promising to exclude DVT in pregnancy without the need for diagnostic imaging. Validating the safety of a simple, non-invasive, widely available approach to suspected DVT in pregnancy would be an important advance in maternal health.

A prospective cohort diagnostic management study in pregnant women with suspected DVT, with three-month follow-up for symptomatic VTE will take place in multiple centres in Canada.

After obtaining informed consent, all patient will have the LEFt clinical decision rule applied by the attending physician and will have D-Dimer testing (D-Dimer results of test performed within 24 hours will be accepted and do not need to be repeated).

Patients with an "unlikely" LEFt score of 0 or 1 point and a negative D-dimer will not undergo diagnostic imaging.

Patients with either a "likely" LEFt score of 2 or 3 points or a positive D-dimer will undergo either a single complete leg vein compression ultrasound (CCUS) (Day 1) or a serial proximal leg vein (CUS) (Day 1 and Day 7).

All patients will be followed for 3 months for symptomatic VTE.

Open or close this module Conditions
Conditions: Pregnancy
Suspected Deep Vein Thrombosis
Compression Ultrasound
D-dimer
Keywords: clinical decision rule
Open or close this module Study Design
Study Type: Observational
Observational Study Model: Cohort
Time Perspective: Prospective
Biospecimen Retention: Samples Without DNA
Biospecimen Description: At presentation, a blood sample will be collected for clinical D-dimer tested in real time and a sample will be collected and the plasma will be frozen for analysis at the end of study using Vidas D-dimer on all patient samples.
Enrollment: 366 [Anticipated]
Number of Groups/Cohorts 1
Open or close this module Groups and Interventions
Groups/Cohorts Interventions
Pregnant women with suspected DVT
Pregnant women presenting with suspected DVT will have the LEFt clinical decision rule applied by the attending physician and will have a clinical D-dimer test done.
LEFt clinical decision rule

The LEFt rule

Predictor Points Left leg symptoms +1 Extremity swelling (≥ 2 cm difference in calf circumference +1 First trimester symptom onset +1

Clinical probability Unlikely: 0 or 1 point Likely: > 1 point

Open or close this module Outcome Measures
Primary Outcome Measures:
1. Number of VTE, in patients deemed DVT "unlikely"
[ Time Frame: 3 months after presentation ]

The primary outcome will be the number of VTE (any DVT (distal or proximal), PE (sub-segmental or greater PE), death attributable to VTE) documented during the three-month follow-up in those patients left untreated for DVT on the basis of the study's initial diagnostic management (see Figure 2) i.e. not doing CUS on patients with an "unlikely" LEFt score (0 or 1 points) and a negative D-dimer
Secondary Outcome Measures:
1. Number of VTE, in all patients
[ Time Frame: 3 months after presentation ]

The number of major VTE events (any proximal DVT, segmental or greater PE, death attributable to VTE) documented during the 3-month follow-up in the patients. Some clinicians may not treat distal DVT or sub-segmental PE in pregnancy, instead following these patients with serial US imaging, and hence may prefer to focus on this outcome that excludes distal DVT and sub-segmental PE.
2. Proportion of women requiring CUS
[ Time Frame: Baseline ]

The proportion of women requiring CUS using the study's diagnostic strategy (i.e. no imaging in patients with an "unlikely" LEFt score (0 or 1 points) and a negative D-dimer). We anticipate that an important proportion (>40%) of women will be able to avoid the need for CUS imaging based on safely excluding DVT on the basis of an "unlikely" LEFt (0 or 1) and a negative D-dimer. However, if this proportion is very low (<5%) this may argue against the widespread adoption of our proposed diagnostic management strategy even if it proves to be safe.
3. Average number of CUS in pregnant women with suspected DVT
[ Time Frame: 7 days from initial presentation ]

The mean number of ultrasounds per patient with suspected DVT. In the study by Chan, validating serial CUS in pregnancy, the mean number of US per patient was 2.8630. We anticipate that we will be able to reduce this by >40% with our diagnostic approach.
Open or close this module Eligibility
Study Population: Unselected pregnant women presenting with suspected deep vein thrombosis
Sampling Method: Probability Sample
Minimum Age: 16 Years
Maximum Age:
Sex: Female
Gender Based:
Accepts Healthy Volunteers: No
Criteria:

Inclusion Criteria:

  1. Unselected pregnant women (preciously documented positive beta hCG on urine or serum pregnancy tests) with.
  2. Suspected acute symptomatic deep vein thrombosis

Defined as:

  1. new leg swelling or edema with onset in the last month or
  2. new leg pain (buttock, groin, thigh or calf) with onset in the last month.

Exclusion Criteria:

  1. Prior major VTE (proximal DVT or segmental or greater PE)
  2. Below the age of legal consent in jurisdiction of residence (18 years old for Quebec and 16 years old for rest of Canada)
  3. Unable or unwilling to provide informed consent
  4. Concomitant symptoms of suspected pulmonary embolism (chest pain or shortness of breath or syncope/pre-syncope or unexplained tachycardia)
  5. Need or plan for ongoing anticoagulant therapy (>2 weeks), at any dosage (i.e. prophylaxis or treatment dosage), throughout the ante-partum period
  6. Need for therapeutic anticoagulant therapy in the post-partum period (i.e. patients that are/will be treated for superficial phlebitis, mechanical valves, atrial fibrillation or other indications).
Open or close this module Contacts/Locations
Central Contact Person: Marc A Rodger, MD
Telephone: 613-737-8899 Ext. 74641
Email: mrodger@ohri.ca
Central Contact Backup: Anne Marie Y Clement
Telephone: 613-737-8899 Ext. 73389
Email: amclement@ohri.ca
Locations:
Open or close this module IPDSharing
Plan to Share IPD:
Open or close this module References
Citations:
Links:
Available IPD/Information:

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